Department of Cell Biology

Subjects:

1. The role of heparin-binding EGF-like growth factor in development.
2. The mode of actions of membrane-anchored growth factors.
3. Ectodomain shedding mechanism of EGF family growth factor.
4. Physiological role of CD9 and the tetraspanin family proteins.
5. Epigenetics in germ cells: About 40% of the testicular germ cell specific genes are retroposons, most of which contain CpG island within their ORFs. We discovered that the methylation of the CpG islands in the ORF represses its promoter in somatic cells and that demethylation is necessary for gene expression in spermatogenic cells. We are analyzing the molecular basis of the methylation in a distinct genomic region in germ cells.
6. Transcriptional regulation of germ cell specific genes: Testicular germ cell-specific genes are regulated by short upstream regions. These specific promoters lack known elements, including the TATA-box and initiator. We are characterizing the unique molecular mechanisms of the preinitiation complex formation for transcription in germ cells.

Published Papers

1. Tetraspanin protein (TSP-15) is required for epidermal integrity in Caenorhabditis elegans.

   Hiroki Moribe, John Yochem, Hiromi Yamada, Yo Tabuse, Toyoshi Fujimoto and Eisuke Mekada

   J Cell Sci, 117 (Pt 22), 5209-5220, 2004.
2. Suppression of the biological activities of the epidermal growth factor (EGF)-like domain by the heparin-binding domain of heparin-binding EGF-like Growth Factor.

   Risa Takazaki, Yuji Shishido, Ryo Iwamoto and Eisuke Mekada

   J Biol Chem, 279 (45), 47335-47343, 2004.
3. Heparin-binding EGF-like growth factor is a promising target for ovarian cancer therapy.

   Shingo Miyamoto, Michinari Hirata, Ayano Yamazaki, Takuya Kageyama, Hidetoshi Hasuwa, Hiroto Mizushima, Yoshihiro Tanaka, Hiroshi Yagi, Kenzo Sonoda, Masahiro Kai, Hideo Kanoh, Hitoo Nakano and Eisuke Mekada

   Cancer Res, 64 (16), 5720-5727, 2004.
4. Tetraspanin protein CD9 is a novel paranodal component regulating paranodal junctional formation.

   Tomoko Ishibashi, Lei Ding, Kazuhiro Ikenaka, Yoshiro Inoue, Kenji Miyado, Eisuke Mekada and Hiroko Baba

   J Neurosci, 24 (1), 96-102, 2004.
5. Transient expression analysis of the mouse ornithine decarboxylase antizyme haploid-specific promoter using in vivo electroporation.

   Akiko Ike, Hiroshi Ohta, Masayoshi Onishi, Naoko Iguchi, Yoshitake Nishimune and Masami Nozaki

   FEBS Lett, 559 (1-3), 159-164, 2004.
6. Gene structure and evolution of testicular haploid germ cell-specific genes, Oxct2a and Oxct2b.

   Masayoshi Onishi, Teruo Yasunaga, Hiromitsu Tanaka, Yoshitake Nishimune and Masami Nozaki

   Genomics, 83 (4), 647-657, 2004.
7. The adaptor molecule FADD from Xenopus laevis demonstrates evolutionary conservation of its pro-apoptotic activity.

   Kazuhiro Sakamaki, Chiyo Takagi, Katsuya Kominami, Shin-ichi Sakata, Yoshio Yaoita, Hiroshi Y Kubota, Masami Nozaki, Shin Yonehara and Naoto Ueno

   Genes Cells, 9 (12), 1249-1264, 2004.

Link

http://www.biken.osaka-u.ac.jp/